We are using Sip phones. I’ve tried this with X-Lite and Mizutech webphone. Same result.
An extension dials an external phone number. The person picks up. After a few seconds the external person hangs up. If the internal extension does nothing, the call can take up to 30 seconds to disconnect. In some cases the system will actually try to call the external person back. This only seems to happen with comcast and other triple play type providers. Cell phones work fine.
We also noticed the same thing with a nexVortex SIP trunk on FreePBX. In our case, it’s only outbound calls though, that have the disconnect problem, and ours was always timed at 30 seconds. Inbound calls, however, if the far-end person hangs up, will disconnect immediately.
I have an open ticket with nexVortex about this, but haven’t heard back from them, other than them saying they will check around with their tech’s and get back with me…
I’ve been working with NexVortex trying to resolve this issue. I’d have to say they have been very cooperative. What the final result was I added below. Are you using any other SIP providers? If so, do you have the same issue? I will be adding 2 to 3 more providers. I will see then if it happens with the new providers as well.
This appears to be a problem with [the person you called] phone service. The call examples that you have provided show nothing unusual. The fact that calls to mobile phones work as expected is further evidence that you need to pursue this issue with the other ITSP you are [calling]. For every call example you have provided that you state is showing a delayed disconnect on the originating side, we are relaying the BYE to your network within milliseconds of receiving it from our PSTN gateway. We perform this piece of the call in the same way regardless of who you call (cell or your other ITSP).